Exportable textures - Multiple patterns with the same shadows?

I’m making an object that I’d like to have in multiple different patters.

All I want to be able to change is the pattern or color. I want the shadows to remain the same, naturally. But - the shadows and patterns need to be exported in a PNG each time the pattern is changed.

Essentially I need, lets say 5 exported textures. All with the same shadowing, different colors.

It seems impossible to me to paint shadowing in Photoshop instead of within blender seeing the actual curves - but is that how it needs to be done?

Any tips would be great!